Michigan's explosive outbreak of diarrheal parasite jumps to over 1,200 cases
Michigan has reported 1,251 cases of Cyclospora cayetanensis infection as of July 9, with 44 hospitalizations. The outbreak began in late June and has already far exceeded the state's typical annual tally.
Cases of Cyclospora cayetanensis, a microscopic parasite causing explosive diarrhea, continue to surge in Michigan, according to the Michigan Department of Health and Human Services (MDHHS). As of July 9, the state has confirmed 1,251 cases, including 44 hospitalizations. Neighboring Ohio is also seeing a rapid rise, with reports of over 500 cases.
The outbreak started with two cases reported on June 22 and escalated sharply in early July. On July 4, MDHHS reported 572 cases. A single-day record of 239 cases was set on July 8, followed by 159 additional cases on July 9.
The epicenter is in southeastern Michigan, where health officials are working to interview patients and trace the source(s) of contamination. Cyclospora cayetanensis is a single-celled protozoan that spreads through contaminated food or water, typically produce. It is shed in feces.
The U.S. typically sees 2,000 to 5,000 cyclosporiasis cases annually, with peak transmission in summer. However, Michigan's outbreak is unprecedented: the state's yearly average is about 50 cases, but July alone has already recorded 25 times that number. Investigators have not yet identified the specific source of infection.
